Progress towards Damage Diagnostics & Prognostics using SOA Computed Tomography Speaker: Joseph M. Wells, Sc.D. Associate Director for Materials Science & Engineering U.S. Office of Naval Research Global – London
[email protected] Office: +44(0) 1895‐61‐6282 Mobile: +44(0) 774‐074‐0921
2nd International Conference of Engineering Against fracture, (ICEAFII) Mykonos, Greece 22‐24 June, 2011
Overview • Introduction • Damage Diagnostic Approaches – Invasive – Non‐Invasive
• • • • •
Damage Characterization & Visualization Predictive Modeling, Validation & Verification Application Areas What’s Next? Summary Comments
Introduction • For structural materials, failure ultimately occurs due to the initiation and growth of pre‐existing defects or service induced damage. • One can try to monitor the operating performance (health) of the structure or do non‐invasive damage diagnostics to locate and characterize such damage (or do both!). • Predicting failure without the due consideration of physical defects or damage within the material is an inexcusable omission. • The challenge, of course, is: – to develop high resolution (and optimally, field portable) non‐ invasive damage diagnostic tools for true multi‐scale volumetric damage diagnostics and analysis. – Reduce volumetric damage characterization data down to descriptive yet tractable modeling parametrics. – Incorporate such damage knowledge into truly PREDICTIVE materials/structural component failure models.
Introduction Cont. • Prognostic ‐ prog∙nos∙tic/präg nästik/ Noun: An advance indication or portent of a future event. • “Descriptive” simulations masquerading as “Predictive” models. – Finite Element simulations using adjustable parameters which are “calibrated” for individual events of known results.
• “Predictive” models approximate material ‐ structural behavior of events with otherwise un‐ known final results.
Background •
Previous Related Workshops (co‐ organized by author) – Feb. 2006 “Role of Damage in the Ballistic Impact Behavior” at Arlington, VA {Army Research Office} – 1‐3 June 2010 “High Resolution, Non‐ invasive Damage Diagnostics and Predictive Modeling of Materials/Structural Behavior” – Ruislip, UK {ONRG} – March 2011 “TomoDamage II” – 2nd High Resolution Non‐Invasive Damage Diagnostics and Predictive Modeling Workshop –Diamond Light Source {ONRG/ONR/EOARD/AFRL/DTRA/DSTL /AWE} – 2012 (Date TBD) – “TomoDamage III” being planned for EMI‐Fraunhofer Institute,
[email protected]
Damage Diagnostic Approaches • Invasive (i.e. destructive) – Sectioning (2D) or progressive sectioning (3D)
• Non‐Invasive: – Indirect functional monitoring (eg. vibration analysis) – Traditional NDT (2D & 3D) (eg. ultrasound) – 3D Computed Tomography (also laminography); Many Forms: • X‐ray (micro and meso‐tomography), XCT • Neutron Tomography ‐ Optical Projection Tomography • Electron Beam Tomography ‐ Atom Probe Tomography • Ultrasonic Tomography ‐ Electrical Capacitance Tomography • Positron Emission Tomography ‐ Optical Coherence Tomography • Others….
Tomography Modalities Table 1. Multiple Tomographic Modalities Type of Tomography
Source of data
Atom Probe Confocal Microscopy
Ions Laser Scanning Confocal Microscopy
Cryo‐electron Electrical Capacitance Electrical Resistivity Electrical Impedance Electron Beam Tomography Functional Magnetic Resonance Imaging Magnetic Induction Magnetic Resonance Imaging Neutron Ocean acoustic tomography Optical coherence tomography Optical projection tomography Positron emission tomography Quantum tomography Single Photon Emission Computed Tomography
Cryo‐electron microscopy Electrical Capacitance Electrical Resistivity Electrical Impedance Electrons Magnetic Resonance Magnetic Induction Nuclear Magnetic Moment Neutron Sonar Interferometry Optical microscope Positron emission Quantum state Gamma ray
Seismic tomography Thermoacoustic imaging Ultrasound‐modulated optical tomography
Seismic waves Photoacoustic spectroscopy Ultrasound
Ultrasound transmission tomography X‐ray tomography
Ultrasound X‐ray
Modified from Wikipedia ‐ http://en.wikipedia.org/wiki/Tomography
Abbreviation APT LSCM Cryo‐ET ECT ERT EIT EBT or 3D TEM fMRI MIT MRI NCT OCT OPT PET SPECT
TAT UOT UT XCT
Some Expertise Centers • X‐ray CT, XCT: – USA: LANL, LLNL, Carl Zeiss IMT, Ford, ARL, AFRL, NRL, ..etc. – UK: ‐U. Manchester (P. Withers) ; ‐ U. Southampton (I. Sinclaire) – EU: EMPH, French (???), Germany (EMI‐Franhofer, BAM)
• Neutron CT: – USA:Oak Ridge Natl Lab., U.Tenn (D. Panumadu) – EU: PSI‐Switzerland; Germany; Austria; Italy; France; UK; etc…
• Electron Beam CT: Karlsruher Inst. For Technology, Germany; ESRF‐ Grenoble, Fr; EMAT‐Antwerp, Belgium; Utrecht, The Netherlands; Japan, USA, etc…
• Synchrotrons: – UK (Diamond); France (Grenoble); USA (UCBerkley, Stanford, Argonne, etc.),….
Physical Damage Perspective • Defect/Damage can be considered as ….any physical change in the condition of a material structure which results in a decrement in its structural integrity and/or functionality. • Multi‐scale aspects…nano‐ micro‐ meso‐ macro • Characterization of damage…nature, extent, shape, size, • Visualization of damage…3D morphology vs 2D planar projection, asymmetric vs axisymmetric , real time vs post‐ mortem, etc.
• Complexity… mixed modes, asymmetry, convoluted, • Other..???
Damage Characterization & Visualization (Example Application of Ballistic Impact Damage)
Impact Damage Has Many Forms! What Damage Manifestations Do We Look For (Beyond “Detection”)? Defect Characteristics: IMPACT DEFECTS • Surface Irregularities • Dimensional Variants • Density Variations • Microstructural (e.g. twining, G.B. variations) • Cracking (various forms) • Ceramic Fragmentation • Porosity (Inhomogeneous) • Residual Proj. Fragments • Others…(TBD)?
• Spatial Location • Size, Shape, Volume, • Statistical Distribution Relationships of Defects to: • Detection/Characterization Capabilities • Probability of Detection • Ability to Segment • Ability to Quantify & 3D Map • Data Format for Models • Effect on Penetration • Ballistic Performance
Ballistic Impact Event: 1.
2.
BAD*
3.
* Behind Armor Debris
1. Penetrator Behavior – Blunting, Erosion, Fragmentation
•
3. Target Damage –
2. Impact & Penetration – Dwell, Initiation, Penetration
“Traditional Penetration Modeling”
+
– – – – – – – –
Surface Cavitation / Radial Expansion Ring & Radial Cracks Conical & Laminar Cracks Hourglass & Spiral Cracking Bulk Ceramic Fragmentation Embedded Fragments Impact Induced Porosity Other…..
Future Physical Damage‐based Modeling
Impact Observations & Diagnostic Tools Dynamic Impact Events:
• •
• • •
Projectile Impact ‐ Surface Interaction / Vpenetration Impact Shock Wave: – Compressive, Shear, Tensile Reflection – Interference / Reinforcement – Loading / Unloading Effects Dynamic Strain Rate & Strain Gradient Effects Transient Thermal Gradient Effects Real Tine Damage & Shock Wave Evolution (Edge on Impact)
Diagnostic Tools Flash X-rays Hi Speed Camera Modeling, Simulation, & Prediction
Post ‐ Impact Damage Observables:
• • • • • • • • •
Surface: Erosion, Cratering, Rubble Mixing, Flow Multiple Cracking Morphologies Asymmetrical Target Radius/Dia. Changes Impact‐Induced Voids/Porosity Distribution Residual Penetrator Fragments Target Material Fragmentation Microstructural Changes Penetration Cavity Features Others?
Visual Destructive Sectioning Ultrasonic NDE Digital X- rays Microwave XCT (Meso- & Micro) Other ??
Schematic of X‐ray Tomography, XCT
XCT scanning approaches - 3D Microfocus with a planar detector array- (left) and 2D Meso/Macro XCT with a linear detector array (right).
XCT Resolution range as a function of object size and x‐ray facility type
Also f(Density)
An empirical relationship between the material density and maximum beam path length for the 225kV XCT
(With î Power)
(Courtesy of M Glasow, C. ZeissIMT)
Damage Feature Presentation
3D XCT Impact Damage Visualizations
TiB2 1S w/o Prestress Ring
As = 4794 mm2 V = 2076 mm3
Hour-Glass & Spiral Cracking Indications –surfaced point cloud*
TiB2 2S with Prestress Ring
As = 8911 mm2 V = 2859 mm3
Damage Profile by Depth
Segmented Fragments & Impact‐Induced Porosity
Porosity
Al2O3 ‐ Fragment Axial X‐Sections
Current SOA for Impact Damage Diagnostics •
Complete volumetric digitization of both metallic and ceramic terminal ballistic targets demonstrated.
•
3D rendering of high resolution virtual solid object target reconstructions
•
Virtual sectioning of such targets on arbitrarily oriented planes revealing multiple complex impact damage features.
•
3D Visualization of multiple impact cracking modes (Includes the detection of 3‐D spiral and hourglass shaped cracking modes not previously reported in the ballistic literature).
•
Segmentation and in‐situ metrology of residual projectile fragment distributions
•
Quantification and 3D visualization of impact‐induce porosity (void) distributions.
•
Axisymmetric quantification and 3D mapping of impact cracking & projectile fragment damage.
•
XCT Damage Diagnostics demonstrated for Transparent as well as Opaque targets and light weight cellular impact & blast resistant targets.
• Separation of damage type • Relative significance • Approximate Math Descriptions • Morphology • Extent • Size
Predictive Modeling
• Diagnostics • Type • Location • Extent • Size • Shape • Metrology • Visualization • Analysis
Predictive Modeling
Representation
Damage Knowledge
Damage
• Verification of descriptive equations • Failure Mechanisms • Failure Model • Validation
Predictive Modeling • True Predictive Modeling for Materials / Structure Failure Behavior is Difficult and not often seen! • Failure depends on material structural defect/damage condition (Structural Integrity) as well as loading condition. • Different defects/damage features contribute to failure in different ways and should be accounted for in predictive models. • Need full identification and characterization of defects/damage features present (including 3‐Dimensional morphology & size) • Defect/Damage feature knowledge needs to be formulated into realistic representations/parameters capable of inclusion into mathematical models • Defect/damage features present a pathway to understanding and mitigating failure mechanisms "A pessimist sees the difficulty in every opportunity; an optimist sees the opportunity in every difficulty." ‐ Winston Churchill
Missing Physical Damage Details in J‐H Models Damage Processes? •Micro-cracked Comminuted Zone •Voids & Bulk MesoCrack Formation Outside of C-Zone? •Dynamic Constraint of Comminuted Zone?
Ref. Johnson & Holmquist http://www.x-cd.com/papers/cesp_v26_i7_003.pdf
•Gradual Loss of Structural Integrity with Evolving Damage? •Increasing Penetration?
• Physical Damage Definitions, Types, Extent, & Morphological Details? • Relationship of Bulk Damage Evolution to C-Zone Structural Stability? • Relationship of C-Zone Structural Stability to Penetration Process?
Size Scale Relationships
Ref: NAS/NMAB Report 2010 ‐ Research Opportunities in Corrosion Science and Engineering
Validation & Verification • Damage Data Base for specific applications • Deconvolution of damage data into pragmatic informatics • Development of modeling expressions for critical damage features and their influence • Verification – (purely mathematical) ensures we are solving the equations right • Validation – (assesses the physical merits of the equations) i.e. ensures we are solving the right equations! • Predictive Models – for when we don’t know the answer beforehand!
Examples of XCT Application Areas • • • • • • • •
Ballistic Impact Tomographic damage Blast characterization included in current Fire Damage ONR/ONRG S&T research programs Corrosion Fatigue Damage High Temp Degradation Bio‐inspired Materials Development Others ??
What’s Next???
The Damage Linkages ↑↑ Ballistic Matls/Design/Performance Armor Ceramic Matl Development
Design – Matls Selection- Matls Improvements – Ballistic Performance Knowledge Base
↓↓ Transition Time & Cost
Damage Tolerant Architectural Design Model Development Model Verification Model Validation
Analytical & Computational PENETRATION Models Models & Simulations
• • • •
Traditional Constitutive relations, Σεf, etc. Mesh Size & Alignment Hydro-code CTH, AUTODYN, etc. Finite Element Analysis
• Penetration Observations • V50, DOP Testing
DAMAGE Diagnostics
NDE Modalities: XCT + XµCT+??
Non-Traditional (Physical Features) • 3D Impact Cracking Variants – (ring, radial, conoid, laminar, + spiral)
• Bulk Ceramic Fragmentation • Residual Penetrator Fragments • Impact-induced Porosity
Empirical Armor Ceramics ----Fab.--Shoot --Look
Schematic XCT Technology Time-Line ?? XCT Engineering – Terminal Ballistics 2008
2012
~ Near-Term
~
2016
Mid-Term
~
2020
Long-Term
XCT Diagnostic Capabilities Segmentation & Analysis of Ballistic Fragments & Host Ceramic Fragmentation Impact Induced Porosity Characterization Segmentation & Analysis of Cracking Damage Morphology Asymmetric Damage Quantification & 3D Mapping Damage Mode Deconvolution Dynamic Real Time Tomography !!!!……….
XCT Diagnostics Applications Characterization of Damage Features in Real Ballistic Targets Damage Quantification & 3D Mapping tied to Damage Model Development Baseline Calibration of Alternative NDE Modalities for Damage Characterization Prioritization of Damage Modes wrt Damage Resistance / Tolerance Predictive Damage-Based Numerical Modeling Improved Armor Ceramic Material Development !!!!!……….
The Way Ahead • Identification, characterization, and analysis of significant damage morphological types under specific target/ (ballistic) experimental conditions; • Effective representation and incorporation of such damage features into evolving computational (ballistic) damage modeling activities; • Determination of the degradation of the structural integrity and the consequential effects of such damage details on the penetration phenomena and, ultimately, the overall (ballistic) performance; • Application of validated and verified (ballistic) damage models to guide the design and development of more damage‐resistant/damage‐tolerant (armor) materials.
Perspective
Outline showing the basic processes of cognitive visualization and analysis for impact damage characterization.
Schematic indicating the added dimensionality of 3D Damage Analysis and its potential effect on improving performance.
“In these days, a man who says a thing cannot be done is quite apt to be interrupted by some idiot doing it. “ ‐ Elbert Green Hubbard
Summary Comments • Need greater numbers of non‐medical tomography practitioners. • Tomography damage assessments are best non‐invasive characterizations & 3D visualizations available. • Need faster XCT scanning / analysis capabilities • Need Real ‐Time Damage Evolution Diagnostics • Need to understand damage mechanisms, kinetics, & consequences • Need greater collaboration between Damage Diagnosticians, Experimentalists,& Modelers • Predictive models for ballistic impact need to incorporate damage as well as penetration considerations. • Predictive Models need to be reasonable, but not ultra precise. • Predictive Models are needed for guidance, to reduce the burden of extensive and costly empiricism. • Predictive risk assessment models can greatly benefit from real damage assessments.
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“We are continually faced by great opportunities brilliantly disguised as insoluble problems” ‐ Anon All truth passes through three stages: First, it is ridiculed; Second, it is violently opposed; and Third, it is accepted as self‐evident. ‐ Arthur Schopenhauer
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Backup Slides
Broaden Applications of XCT Damage Assessment Failure Analysis Interior Dimensioning Non-Intrusive Inspections ( mail, baggage, cargo, etc. Prototype Inspection & Quality Assurance Reverse Engineering & Design Verification Research – Model Development and Verification Scientific Quantitative Data Visualization, Image Processing and Analysis.
References • • • • • •
J.M. Wells, On Incorporating XCT into Predictive Ballistic Impact Damage Modeling. Proc. of 22nd Int. Ballistics Symp., ADPA, v2,. 1223‐1230, 2005. J.M. Wells, On the Role of Impact Damage in Armor Ceramic Performance. Proc. of 30th Int. Conf. on Advanced Ceramics & Composites‐Advances in Ceramic Armor, 2006. J.M. Wells, On Continuing the Evolution of XCT Engineering Capabilities for Impact Damage Diagnostics., Proc. 31st Intn’l Conf. on Advanced Ceramics & Composites, ACERS, 2007. J.M. Wells and R.M. Brannon, Advances In X‐Ray Computed Tomography Diagnostics of Ballistic Impact Damage, Metallurgical and Materials Transactions A, v. 38A, 2944‐2949, 2007. Brannon, Rebecca M.; Wells, Joseph M.; Strack, O. Erik, Validating Theories for Brittle Damage , Metallurgical and Materials Transactions A ,38A, 2861‐ 2868 , 2007 Shen, Jie; Mao, Jianghui; Reyes, German; Chow, Chi L. ; Boileau, James; Su, Xuming; Wells, Joseph M. , A Multiresolution Transformation Rule of Material Defects , International Journal of Damage Mechanics, v18, 739‐ 758 ,2009
